This invention relates to a process for producing nutrient compositions from animal blood. In one aspect, this invention relates to a process for producing feed supplements containing blood solids and other proteinaceous materials. Furthermore, this invention relates to a process for producing feed supplements for ruminant animals comprising nutrient lipids microencapsulated in alkaline-treated blood solids which, when ingested by a ruminant, pass through the rumen of the animals and are assimilated within the abomasum and lower gut of the animal.
Animal blood obtained in a typical slaughter house operation is either dried to form blood meal or is expelled as effluent. More specifically, liquid blood obtained as a by-product in slaughter house operations is a low value material that is often dumped by some smaller meat packers because they have no use or no market for the material. Larger meat packing facilities have dryers to dry the blood to form a meal which is sold mainly as a fertilizer or animal feed stuff. In general, the blood meal is processed into a dry form on or near the slaughter house premises. Typically, blood is collected in holding vessels and periodically, when a sufficient quantity is collected, it is subjected to one of several possible heating processes which in effect drives the volatile constituents therefrom and thus the blood solids are recovered. This is conventionally accomplished in a batch-type blood cooker, a ring dryer or a spray drying operation. These various drying processes utilize relatively large quantities of energy and produce obnoxious odors when released into the atmosphere and surrounding environment. In addition, refrigeration of the blood may be required in the case of some spray drying operations. Substantial quantities of the nutrients in the blood can be lost through biodegradation which may occur during typical storage and transit conditions. Substantial degradation of the nutrient value of blood solids is typical when the blood is exposed to the high temperatures associated with blood cooker operations. Thus, a more efficient process for utilization of blood, fat and collagen obtained from slaughter house operations is needed, i.e., a method of producing blood, fat and collagen into a usable and thus salable commodity is needed which can be carried out without an undue expenditure of energy and without polluting the environment with obnoxious odors or effluents.
Furthermore, it is desirable to develop nutrient feed stuffs for animals which contain effective and nutritional amounts of nutrient lipids. Earlier researchers have found that it is extremely difficult to feed large quantities of lipid to ruminant animals, i.e., quantities of lipid greater than 4 to 6%. Specifically, the ruminant animal has a multi-gastric system with a first stomach known as a rumen wherein bacteria generally known as microflora are present. These microflora have the ability to break down proteins and lipids, among other things, and hydrogenate unsaturated lipids. Therefore, a significant portion of the unsaturated lipid contained in typical ruminent feeds is hydrogenated in the rumen by the microflora and is subsequently assimilated by the animal as saturated fat. Additionally, the rumen has a low tolerance to feeds containing high concentrations (4 to 6%) of either saturated or unsaturated lipids. This low tolerance produces severe gastric upset when feeds containing high concentrations of unprotected lipids are ingested. For example, when large quantities of dietary lipids are fed to ruminants over and above the 4 to 6%, the ruminant's consumption of total feed intake is typically reduced bringing about a dietary situation wherein there is not enough caloric intake to provide for effective net energy production and in some cases, no energy maintenance of the animal. In addition, digestive disturbances occur because of the lipids floating on the liquid in the rumen and the ruminant will drastically reduce its consumption until it has digested the lipid in the rumen. Furthermore, when such lipids are unsaturated, the rumen's microflora will hydrogenate most of the same and little of the unsaturated lipid will become incorporated into the ruminant's meat or milk.
Several processes have been proposed for encapsulating proteinaceous and lipid materials, in order to effect bypass of such materials through the rumen of the ruminant animal. For example, U.S. Pat. Nos. 3,619,200 and 3,829,564 disclose such processes. Particularly interesting is that process disclosed in U.S. Pat. No. 3,619,200, issued to Ferguson et al. and entitled "Method and Food Composition for Feeding Ruminants". The Ferguson et al. reference states that proteinaceous feed can be protected from breakdown within the rumen of a ruminant animal by modification of the protein itself, by application of a protective coating, or by a combination of the modification of the protein and the protective coating. One particular method set forth is the formation of a protective coating of a formaldehyde-protein complex.
Recently, a process has been developed which encapsulates nutrient lipids in a protective protein-aldehyde complex coating. This process is disclosed in U.S. Pat. No. 3,925,560, issued Dec. 9, 1975. The protein-aldehyde coating covering the lipid is not susceptible to breakdown in the rumen, but is susceptible to breakdown in the abomasum and lower gut. This process includes finely dividing the lipid material into discrete particles or globules and forming an aqueous emulsion or dispersion of finely divided lipid and a proteinaceous material. The aqueous emulsion can then be reacted with an aldehyde such that the finely divided lipid particles are encapsulated in a protein-aldehyde complex. The emulsion is treated with aldehyde and dried to form a coated particle solid.
Although the above mentioned processes have been successful in producing a feed supplement resistant to rumen microflora, new methods for producing such feed supplements are constantly being sought, especially processes employing waste materials which have little or no value. It is to such a feed supplement and process for producing same that the invention is directed.